Charles tcwnsekb b aisle y



Apr. 17, 1923. 1,452,334

c. T. BAISLEY TELEPHONE RECEIVER Filed may 11. 1922 Fig. 1. f

Y6 22 22 JA ll Ilunmi;

INVENTUR Can/ 1.55 7. Efl/JL 5 ATTORNEY Patenteclf-tpr. 1'5, 1923.

UNITED STATES PATENT OFFICE.

CHARLES TGWNSEIJD BAISLEY, Y2? NORTH EDGECOMB, IEAINE, ASSIGNOR TO IVIAN- nnarrnn ELECTRICAL SUPPLY co. me, or new YORK,

MASSACHUSETTS.

N. Y., A CORPORATION OF TELEPHGNE RECEIVER.

Application filed May 11, 1922.

1 "0 all to from it may concern it known that ii, Cit- Armies Towrzsnno BAZSLEY, a citizen of the Un ted States oi America, residing at l'lor th itdgecornb, 1n the county oi Lincoln and state of Maine, have invented certain new and useful Im provements in Telephone hiecervers, or which the following is a specincatlon.

My invention relates to telephone receivers, and particularly to receivers of the watch-case type. The particular ob ect or my invention is to provide a receiving ma gnet unit of improved construction which iacilitates its manufacture and its assembly with the related elements or the receiver.

In the accompanying drawings-- Fig. 1 is a plan view of a Watch-case telephone receiver With the d1aphragm and cover detached;

Fig. 2 is a section on the line 2-2, Flg. 1, showing the diaphragm and cap in assembled position; I

Fig. 3 is a perspective of the receiving magnet unit detached; and I Fig. l is a dropped perspective ot the elements oi? the magnet unit.

The receiver comprises an insulating body 5 of cup shape, preferably molded, as usual, from rubber or suitable insulating composition. It carries the usual cover 6, between the flange 7 of which and the upper edge of the side Wall. of the cup-shaped body 5, 1s clamped the vibrating diaphragm 8 ct magnetic material.

Housed Within the casing 5 are the terminals 9 and 10, to Which the lead Wires 11 and 12 are connected. Permanent magnets in the form of horse-shoe plates 13 and 14 are mounted on posts 15 and l6, thebases of which may be molded into the bottom of the casing, and having'bearing shoulders 17 substantially flush With the latter. Underlying the plates 13 and 1 1 are pole straps 18 and 19, pierced at 20 and 21 to fitover the posts 15 and 16, upon Which they, with the magnet plates 13 and 1 1, are clamped in fixed posrtion by the nuts 22. The pole straps are oflset to afford upwardly extending fiat pole pieces 23 and 24-, upon Which the receiving magnet coils 25 and 26 are arranged.

It has heretofore been the commo u practice to mount the magnet coils on the pole pieces 23 and 2 1 independently of each other, and to assemble the two pole straps, With their asso- Serial No. 560,061.

ciated magnet coils, independently of each other W thin the chamber of the receiver, aiter which the windings of the two coils are connected together in series, the parts trued With relation to each other, and the ends of the straps machined after assembly in the receiver. This practice has resulted in inaccuracies in location of the parts With re spect to each other, incident to the manual assembly of the parts, with resulting lack of symmetry of the magnetic field and unsatisfactory functioning of the receiver. Moreover, the machining of the ends of the pole pieces after the parts are assembled in the cup, has resulted in the deposit of particles of metal in the receiving chamber, which interfere with the accurate function ing of the receiver.

The present invention provides a magnet unit Which is completely assembled and machined before insertion in the receiver cup. thus insuring exact location of the poles With relation to each other, facilitating; its assembly in the cup, and preventing the introduction of metal particles into the latter.

The construction Will be readily observed from Figs. 3 and 4:. As indicated, the man'- net coils 25 and 26 are Wound upon paper spools 27 and 28, of a generally rectangular shape, and the ends of the windings vi'hich are to be connected in series are carried out through the end flanges of the spools as indicated at 29 and 30. The opposite ends of .the windings 31 and 32 are carried out at any convenient point from the insulating); jackets which surround the coils, and after theassembly oi. the unit in the cup 5, are connected by a drop of solder, or otherwise, to the plates 33 and 3 1, mounted at the tops of the Wire terminals 9 and 10. An insulating Washer 35 pierced at 36 and 37 to accommodate the pole pieces 23 and 24 accurately spaces the latter and brings their lower ends into exact parallelism. After the coils 27 and 28 have been slipped upon the poles so located, the ends 29 and 30 of the windings are united by a drop oi solder to electrically connect the coils in series. A second insulating Washer 38, preferably oi heavier material, and slotted at 39 and %O. in register With the slots 36 and S7 of the Washer 35, is then forced down upon the pole pieces 23 and 2 1 above the windings. The slots 39 and 40 are of such size that they snugly fit and frictionally engage the pole pieces, thus forming a rigid spacer which accurately positions the same with respect to each other, leaving the poles exposed. In

these dimensions substantially correspond.

In other words, the poles and il-.4 form op posite sides of a square area, which is located, by the position of the base straps l8 and 19 and their supporting posts 15 and 16,

in the precise center of the vibratory diaphragm 8 when the magnets are assembled in the chamber of the receiver.

The exact parallelism of the poles which is assured by the Washer 38 is of great im portance in securing an absolutely symmetrical niagnetic field between the poles. There are consequently no distorting el'lorts on the diaphragm atthe point of magnetic stress on the flow of or cnt through the magnet. Any slight warping which may occur in the annealing of the plates 18 and Walter they have been bent to shape, is of no practical importance after the parts have been assembled with the washers and 38, since the latter hold the plates in rigidly fixed relationship, and the effective portions of the magnet, viz., the poles 45 and 44, are exactly maintained in predetermined position.

The combined effect of the upper and lower washers 35 and 238 is to bind the two poles and their associated windings and base straps, into a unit which may be readily handled without danger of breaking the soldered connection between the ends 9 and 30 of the magnet windings. Consequently, the poles 43 and 44 may be machined. to exact planity before the magnet unit mounted in the receiver. Danger of theintroduction of loose metal particles into the receiver ,chamber is thus minimized.

The precise nature of the insulating washers 35 and 38 is of no essential importance, but I prefer to use a heavy fiber for the up per washer 88, and a lighter fiber for the lower washer 35, which is thus free to ac commodate itself more readily to any inequalities or lack of planity in the base straps 18 and 1,9.

Details of construction may be varied in located b many ways without departing from what I I claim as my invention.

1 claim-- 1. A telephone receiver of the watch-case and engaged thereon above and belowithe coils to locate the poles in accurate parallelism, the upper washer being forced upon the pole pieces to frictionally grip the same and.

thus to secure said partstogether as an assembly unit, substantially as described.

2. A telephone receiver having a pair of pole plates, and mounted thereon a pair of insulating spools haying top flanges apertured between said pole plates, independent windings on said spools; one end of of said windings being carried through the hole in the top flange of'its spool and saidends being connected together to arrange the coils in series, in combination with an lnsnl'ating spacing washer common to said pole plates and overlying sald series connection between the ends of the coils.

5. As an assembly unit for a watch-case telephone receiver, a pair of pole plates with int: base straps offset therefrom in op ante directions, magnet coils arranged on said pole plates, and independent spacing washers common to said pole plates and engaged'thereon above and below the coilsto locate the poles in accurate parallelism, and to secure said parts together asan assembly unit, the windings of one coil being electrically connected in series with the windings of the other coil by a soldered joint (heath the upper spacing washer.

41, As an assembly unit for a watch-case telephone receiver, a pair of pole plates with integral base straps offset therefrom in opposite directions, magnet coils arranged on said pole plates, and'independent spacing washers common to said pole plates and engaged thereon above and belciw the coils to locate the poles in accurate parallelism' and to secure said parts together as an assembly unit, the washer above the coils being more rigid than that below the coils, and being forced upon the pole plates to frictionally grip the same and thus to secure the parts together as an assembly unit.

in testimony whereof l have name to this specification.

cnaenns 'rownsnnn nnIsLnY.

signed my each. 

